Br<i>PARP1</i>, a Poly (ADP-Ribose) Polymerase Gene, Is Involved in Root Development in <i>Brassica rapa</i> under Drought Stress
Gangqiang Cao,
Wenjing Jiang,
Gongyao Shi,
Zhaoran Tian,
Jingjing Shang,
Zhengqing Xie,
Weiwei Chen,
Baoming Tian,
Xiaochun Wei,
Fang Wei,
Huihui Gu
Affiliations
Gangqiang Cao
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Wenjing Jiang
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Gongyao Shi
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Zhaoran Tian
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Jingjing Shang
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Zhengqing Xie
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Weiwei Chen
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Baoming Tian
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Xiaochun Wei
Institute of Horticulture, Henan Academy of Agricultural Sciences, Graduate T & R Base of Zhengzhou University, Zhengzhou 450002, China
Fang Wei
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
Huihui Gu
Henan International Joint Laboratory of Crop Gene Resources and Improvements, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
PARP proteins are highly conserved homologs among the eukaryotic poly (ADP-ribose) polymerases. After activation, ADP-ribose polymers are synthesized on a series of ribozymes that use NAD+ as a substrate. PARPs participate in the regulation of various important biological processes, such as plant growth, development, and stress response. In this study, we characterized the homologue of PARP1 in B. rapa using RNA interference (RNAi) to reveal the underlying mechanism responding to drought stress. Bioinformatics and expression pattern analyses demonstrated that two copy numbers of PARP1 genes (BrPARP1.A03 and BrPARP1.A05) in B. rapa following a whole-genome triplication (WGT) event were retained compared with Arabidopsis, but only BrPARP1.A03 was predominantly transcribed in plant roots. Silencing of BrPARP1 could markedly promote root growth and development, probably via regulating cell division, and the transgenic Brassica lines showed more tolerance under drought treatment, accompanied with substantial alterations including accumulated proline contents, significantly reduced malondialdehyde, and increased antioxidative enzyme activity. In addition, the findings showed that the expression of stress-responsive genes, as well as reactive oxygen species (ROS)-scavenging related genes, was largely reinforced in the transgenic lines under drought stress. In general, these results indicated that BrPARP1 likely responds to drought stress by regulating root growth and the expression of stress-related genes to cope with adverse conditions in B. rapa.
